摘要
鄂尔多斯盆地东北部大牛地气田马家沟组岩溶储层遭受基底复活断裂及多期走滑断裂的影响,由于断裂断距小、类型多、成因复杂,目前对断裂发育特征及其与表生期岩溶关系的认识较为有限。综合利用岩心、薄片、露头、钻测井、地球化学和高精度地震资料,分析了大牛地气田马家沟组断裂的宏微观特征、期次及分布规律,并结合岩溶发育特征,讨论了马家沟组不同性质、不同规模断裂对表生期岩溶的控制作用,得出以下主要认识:①研究区马家沟组发育与表生期匹配的基底复活断裂和小规模层间走滑断裂,平面上西侧断裂级别较东侧大,以改造基底正断层形成的“S”型逆冲断裂为主,东侧呈雁列式排布的北西—南东向层间走滑断裂发育程度高;②基底复活断裂和层间走滑断裂沟通了深部马五_(6)亚段至马一段的岩溶作用,断裂的沟通导致古岩溶在垂向分带的基础上叠加了分区差异性,基底复活断裂发育的区域岩溶作用强,影响层位深;③马五_(6)亚段以上层位为典型风化壳岩溶,以下层位岩溶作用明显受“断裂+易溶岩相”控制,断裂沟通含膏云岩、白云岩等易溶岩相,使得岩溶范围在空间上相互叠置。研究结果为理解鄂尔多斯盆地东北部马家沟组风化壳之下更深层位岩溶发育规律提供了新视角,也为该区未来岩溶储层的勘探提供了新思路。
The carbonate karst reservoir of Majiagou Formation in Daniudi Gas Field is affected by the basement reactivation faults and multi-stage strike slip faults.Due to the small fault throw,varied types and complex genesis,the understanding of the fault formation and their relationships with supergene karstification are limited.Based on the core,thin section,outcrops,drilling,geochemical and high-precision seismic data,the macro and micro characteristics,period,and distribution rules of faults in the Majiagou Formation were analyzed,and the control of different faults with different properties on the supergene karst was discussed.The results show that:(1)Basement reactivation faults and small-scale interlayer strike slip faults matching with supergene karst were developed in Majiagou Formation.The fault level on the west side was larger than that on the east side.The“S”type thrust faults formed by reforming the basement normal faults are the main ones,and the NW-SE interlayer strike slip faults arranged in echelon pattern on the east side were highly developed.(2)The basement reactivation faults and the interlayer strike slip faults connected the karstification from Ma_(5)^(6) sub-member to Ma_(1) Member.The connection of the faults caused the ancient karst to superimpose the regional difference based on the vertical zoning.The basement reactivation faults led to the stronger karstification.(3)The strata above the Ma_(5)^(6) sub-member were typical weathering crust karstification.The karst process of the strata below the Ma_(5)^(6) sub-member was obviously controlled by the faults and easily dissolved rocks.The different types of faults connected easily dissolved rock facies such as gypsum bearing dolomite,which made the karst areas overlap each other in space.This research gives a new perspective for understanding the deeper karst development law under the weathering crust of Majiagou Formation in northeastern Ordos Basin,and also provides a new view for the future exploration of karst reservoirs in this area.
作者
胥旺
邓虎成
雷涛
伏美燕
何建华
吴冬
王瑕
兰浩翔
XU Wang;DENG Hucheng;LEI Tao;FU Meiyan;HE Jianhua;WU Dong;WANG Xia;LAN Haoxiang(College of Energy Resources,Chengdu University of Technology,Chengdu 610059,China;Tianfu Yongxing Laboratory,Chengdu 610217,China;State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation,Chengdu University of Technology,Chengdu 610059,China;SINOPEC North China Oil&Gas Branch,Zhengzhou 450006,China)
出处
《天然气地球科学》
CAS
CSCD
北大核心
2023年第3期431-444,共14页
Natural Gas Geoscience
基金
油气藏地质及开发工程国家重点实验室(成都理工大学)开放基金(编号:plc2020023)
成都理工大学教师发展科研启动基金(编号:10912-KYQD2019-07739)联合资助.
关键词
断裂
构造期次
岩溶作用
马家沟组
大牛地气田
Fault
Tectonic period
Karstification
Majiagou Formation
Daniudi Gas Field
